IOLs are artificial lenses used to replace natural crystalline lenses of patients' when their natural lenses are diseased or otherwise impaired. Under some circumstances a natural lens may remain in a patient's eye together with an implanted IOL. IOLs may be placed in either the posterior chamber or the anterior chamber of an eye. IOLs come in a variety of configurations and materials.
Various instruments and methods for implanting such IOLs in an eye are known. Typically, an incision is made in a patient's cornea and an IOL is inserted into the eye through the incision. In one technique, a surgeon uses surgical forceps to grasp the IOL and insert it through the incision into the eye. While this technique is still practiced today, more and more surgeons are using IOL injectors, which offer advantages such as affording a surgeon more control when inserting an IOL into an eye and permitting insertion of IOLs through smaller corneal incisions. Relatively small incision sizes (e.g., less than about 3 mm) are preferred over relatively large incisions (e.g., about 3.2 to 5+mm) since smaller incisions have been attributed with reduced post-surgical healing time and reduced complications such as induced astigmatism.
In order for an IOL to fit through a small incision, it is typically folded and/or compressed prior to entering the eye where it will assume its original unfolded/uncompressed shape. Since IOLs are very small and delicate articles of manufacture, great care is taken in their handling, both as they are loaded into an injector and as the IOLs are injected into patients' eyes.
It is desirable that an IOL be expelled from the tip of the IOL injector and into the eye in an undamaged condition and in a predictable orientation. Should an IOL be damaged or expelled from the injector in an incorrect orientation, a surgeon may need to remove or further manipulate the IOL in the eye, possibly resulting in trauma to the surrounding tissues of the eye. To achieve proper delivery of an IOL, consistent loading of the IOL into the injector device with limited opportunity for damaging the IOL is desirable.
Various IOL injectors and other devices have been proposed which attempt to address issues related to loading, yet there remains a need for an IOL injector that improves ease and consistency of loading.